A while back I discussed with senior scientist Suzanne Rowe from Ag Research about low emitting sheep. So where are we at with this and does an animal that is better for the environment sacrifice performance or quality? She joined me again this week to discuss.
New Zealand is a world leader in the recent development of breeding sheep that burp less methane which is – a relatively short-lived but greenhouse gas that contributes to climate change, this is well documented.
After three generations of breeding, the lowest emitting sheep in a research flock produced close to 13% less methane than the highest emitters, per kilogram of feed eaten. But questions have remained about whether this low methane trait means sacrifices for the health or quality of the animals, including quality of the meat that is destined for New Zealand’s international markets.
Research relating to the health of the sheep also suggests that breeding for low methane is unlikely to affect issues such as internal parasites, the fertility of adult ewes and the survival of lamb litters. When it comes to wool, low methane breeding was favourable to fleece weight, while it was also favourable to the weight achieved by the animal before slaughter and its body condition.
“Once we knew we could breed for less methane, we set about determining what the impact on the animal might be from birth through to parenthood,” Dr Rowe says. “The work was carried out in flocks across New Zealand using thousands of measures over several years to demonstrate that low methane emissions can be included into breeding goals without sacrificing other key health and performance traits.”
“What we have found is that breeding for lower methane, and the physiological changes we see in these lower emitting animals, do not negatively affect meat quality or those things meat producers are looking for in the animal carcass. The story has some complex biology behind it as we saw that low-emitting animals have different eating behaviours, tending to be grazers rather than gorgers - eating more feed than their high-emitting counterparts, even though the high emitters had bigger stomachs. This ‘little and often’ approach seems to favour laying down muscle instead of fat under the skin, whilst keeping the healthy fats that provide flavour, so meat quality is retained along with the reduced emissions.”
“We think the low-emitting animals may in fact have even greater economic value through decreased fat and increased meat yields. This is critical because farmers need to know that if they are committing to breeding their animals for lower methane, that they are not going to go backwards in their productivity and earnings. This knowledge provides greater incentive to make changes on farms that contribute to New Zealand’s methane reduction goals, and to climate change globally.”
I have not yet met a scientist working in the Ag sector that does not have one eye firmly focused on not only the future of farming in New Zealand but also constantly driving for further improvements in the area of sustainable farming practices. So sheep breeders now have the ability to breed animals with a low methane trait that does not compromise on animal health, lambing percentages or carcass yields. There is a lot to celebrate here and I have no doubt we will achieve the same results in our beef herd through the Informing New Zealand Beef Program. It is gains like this along with all the other environmental work that farmers are doing, that will well and truly set us apart from the rest of the world.
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Angus Kebbell is the Producer at Tailwind Media. You can contact him here.
11 Comments
"New Zealand is a world leader in the recent development of breeding sheep that burp less methane which is – a relatively short-lived but greenhouse gas that contributes to climate change, this is well documented. "
Stop coming after our farmers and our food.
Lets see if we can breed some Politicians that burp less about the Climate Cult !
What's the climate cult? Obviously not those who understand shifting the energy balance of the planet we survive on, is a really dumb idea? It must be those with the religious conviction of "she'll be right", the giant sky fairy will protect us and send us to fluffy clouds once we've fd up planet Earth. If only denial was a force of nature, rather than a cult characteristic.
Yes, it s true that nature chose not to select for some traits we now breed for, which implies that natural selection for these traits did not improve evolutionary fitness. From an ecological perspective, it is no surprise that some measures of improved productivity per animal do not increase evolutionary fitness. For example, nature decided that there were costs as well as benefits associated with increased lambing percentage
However, selection for low methane emission should, all other things being equal, have created animals that were more biologically efficient given that there is an energy cost associated with the methane emission. Accordingly I currently remain somewhat agnostic in relation to whether breeding for low methane emissions will be a pathway to pastoral salvation. I expect that with these designer sheep, if they have a productivity benefit, then it will be under conditions of high ME feed.
A comparative trial, under low, medium and high ME conditions would be very interesting. I think there is a worthwhile hypothesis that the comparative performance may differ depending on feed type.
It is important that scientists don't get too carried away with enthusiasm prior to all of the answers being found. One of the important questions is why do sheep produce methane.
KeithW
"a pathway to pastoral salvation" - that almost reads as if you are arguing against a straw-man, Keith, surely not! Yet to see anyone describe it as such, rather it looks like just another tool in the toolbox.
The problem with arguing natural selection is that the sheep we have are the result of generations of un-natural selection, so distribution of traits in our domestic sheep is no indication of what resulted previously in wild-types - would be fascinating to put some of the wild sheep species in a PAC though. Arguably our breeding programmes could have been selecting for lower methane efficiency given the increased feed intakes, who knows.
I'm reminded of the 'one good lamb, not two poor ones' comment that was sometimes bandied around when the industry started to make serious advances in fecundity, either through selection or composite breeds. Maybe the lower methane effect wont hold across pasture types and maybe there will be a GxE effect (like we see for FE tolerance, but not too many other traits). The use of cross-flock analyses covering a wide range of environments is some initial evidence that it will hold, given the correlation between lower methane output and higher indexes.
A key thing I think is it isn't a binary trait, its not either low or high, there is a range in the EBV and so even if there is a GxE effect, that doesn't rule it out as an option. For example, if ME has an effect because of the rumen, could just have a smaller methane reduction EBV for poorer pasture, the higher EBVs on the farms with higher quality pastures. Horses for courses, perhaps
Will be interesting to see what transpires. The scientists and breeders in the programme so far seem optimistic
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